For 4k Max 2nd Gen (16GB Firestick) - Click Home button on Remote and Click on the 3 boxes and the plus sign and skip to Step 3.

Step 1 - Hold Down the home button on Remote until you see the time

Step 2 - Click on Apps

Step 3 - Highlight the Application you want to move

Step 4 - Click the Menu Button on Remote (button with 3 lines)

Step 5 - Click on Move To Front